1. Field of the Invention
The present invention relates to a seat belt system. More specifically, the present invention relates to an inflatable seat belt system.
2. Technical Background
Seat belts are known to increase the safety of occupants in various motorized vehicles. Seat belt use is often cited as the most useful line of defense in reducing accident related injuries. The actions of consumer groups, governmental agencies, and political activists all reflect the tremendous societal value of seat belt use. Legislation requiring manufacturers to include seat belts in their vehicles has been in place for many years. Recently, laws have been enacted requiring consumers to use seat belts.
The benefits of seat belt use are numerous. In a collision, seat belts may prevent the occupant of a vehicle from striking the interior of the vehicle or other objects within the vehicle, including other occupants. Seat belts aid in keeping the occupant inside the vehicle, where the chances of survival are much greater. Seat belts may also keep the driver behind the wheel and in control of the vehicle in a collision, averting additional collisions, damage, or injuries. Seat belts also enhance the effectiveness of other safety devices. For example, in a vehicle with airbags, a seat belt keeps the occupant in the seat, so the airbag can better protect the occupant.
Seat belts vary in their configuration, but one of the most common types of seat belts is the lap belt. The lap belt includes right and left lap belts that traverse an occupant""s lap and are secured to each other near the occupant""s abdomen. The right and left belts may be secured together by a locking device that may include a latch plate and a buckle. Lap belts are found in many different types of vehicles throughout the world.
Although the lower body is restrained by conventional lap belts, these belts do not restrain the upper body, which may experience rapid and dangerous movement during an accident. This movement is particularly dangerous for passengers in the front seat of an automobile, who may strike the steering wheel, dashboard, or windshield during an accident.
A seat belt system having one or more shoulder belts limits an occupant""s upper body movement in an accident. A 3-point seat belt system includes a lap belt and one shoulder belt that diagonally traverses the occupant""s torso. Another type of seat belt system, which may be referred to as a 4-point seat belt, includes two lap belts and two shoulder belts that meet at a locking device.
As indicated above, to further protect an occupant of a vehicle, airbags have been developed. Airbags may be positioned in a variety of locations throughout the vehicle. Airbags located within the steering wheel aid in preventing the driver from striking the steering wheel and the windshield in the event of an accident. Airbags have also been placed in the dashboard directly in front of the passenger seat in a vehicle or in the interior sides of a vehicle to prevent occupants from striking the doors and windows of the vehicle during an accident.
Previously, sensors were placed in a vehicle""s bumpers to determine when to deploy an airbag. A modern airbag, however, may include an electronic control unit (ECU). The ECU is usually installed in the middle of an automobile. The ECU includes a sensor that continuously monitors the acceleration and deceleration of the vehicle. The ECU sends this information to a processor that analyzes the information with an algorithm to determine whether the vehicle is in an accident.
When the processor determines that there is an accident situation, the ECU transmits an electrical signal to an initiator in, for example, an airbag module. The initiator triggers operation of the inflator. The inflator inflates a textile airbag to prevent injury to the passenger. In some airbag apparatuses, the airbag may be fully inflated within 50 thousandths of a second and deflated within two tenths of a second.
Airbag inflators come in a number of different varieties. Some inflators, which are often referred to as xe2x80x9cstored gas inflators,xe2x80x9d simply store gas in a high-pressure state and release the gas during an impact. xe2x80x9cPyrotechnicxe2x80x9d inflators, by contrast, do not store gas; rather, they contain propellants that, upon ignition, react to produce inflation gas. xe2x80x9cHybridxe2x80x9d inflators utilize compressed gas in combination with pyrotechnics to produce inflation gas. In some instances, the pyrotechnic can also open or rupture a chamber containing pressurized gases, allowing the pressurized gas to escape and inflate into an attached airbag.
In addition, to the embodiments discussed above, airbags have also been placed on seat belts to form what may be referred to as inflatable seat belts. Inflatable seat belts provide an additional element of protection to the occupant and also aid to stabilize the occupant""s head and neck during an accident. These belts also provide a wider surface at which the occupant contacts the seat belt system, thereby distributing the force of the impact over a wider area of the occupant""s body.
However, conventional inflatable seat belt systems suffer from a number of deficiencies. Often the inflatable members are not adequately protected from damage or wear and tear and thus may become useless, or even dangerous, over time. In some embodiments, additional layers of protection have been superimposed over airbags attached to the seat belt webbing, resulting in additional manufacturing time and material costs to a manufacturer. Furthermore, this additional protection may make an inflatable seat belt system cumbersome and difficult for consumers to use and may simply be unsightly.
Additionally, positioning the inflatable seat belt system relative to an occupant is critical to protecting an occupant during an accident. Moreover, maintaining the correct position of the inflatable seat belts is more difficult than with conventional seat belts because inflatable seat belts expand during an accident.
Consequently, there is a need, which is unfulfilled by the conventional systems, for an inflatable seat belt system that provides superior protection to inflatable members of the system so that the inflatable members may properly deploy in an accident.
The apparatus and methods of the present invention have been developed in response to the present state-of-the-art, and, in particular, in response to problems and needs in the art that have not yet been fully resolved by currently available inflatable seat belt systems. The present invention provides an apparatus for enhancing the effectiveness of inflatable seat belt systems. To achieve the foregoing, and in accordance with the invention as embodied and broadly described in the preferred embodiment, an inflatable seat belt system is disclosed which diminishes the risk of injury in an accident.
The inflatable seat belt system may include two shoulder belts and two lap belts. Each of the lap and shoulder belts may be coupled to a locking device, which is selectively lockable by an occupant. The locking device may include a latch plate and a buckle that may be selectively locked together.
Also, the inflatable seat belt system may include one or more anti-submarining (crotch) belts, which are also coupled to the locking device. The anti-submarining belts prevent an occupant from slipping down between the lap belts during an accident and striking objects. Of course, selected embodiments of the inflatable seat belt system may include one or two anti-submarining belts or none at all.
In one embodiment, the two shoulder belts are inflatable, as will be discussed in greater detail below. In such an embodiment, the lap belts may be made from conventional seat belt webbing and be attached to a vehicle (which may include the seat) using retractors or pretensioners, which are known to those skilled in the art.
A user may adjust a length of the inflatable shoulder belts using a cinching mechanism disposed within the locking device. Cinching mechanisms are known in the art and allow for adjustment of the length of the belts during loading of an occupant, but lock into place during rapid acceleration or deceleration that may accompany an accident. The locking device is located proximate an occupant""s abdomen and hence the cinching mechanism is located near an occupant""s hands and may be easily adjusted. Also, because the cinching mechanism is entirely disposed within the locking device (e.g., no cinching buckles are attached to the belts outside of the locking device), a wider range of adjustment levels is provided to the occupant. In addition, a larger portion of the shoulder belts may be inflatable to provide greater protection to an occupant.
In an alternative embodiment, both the shoulder and lap belts are inflatable. In such an embodiment, the inflatable lap belts may be fastened to a vehicle using any number of fixed fastening devices (e.g., bolts or rivets), rather than using retractors. Also, a cinching mechanism, as described above, may be disposed within the locking device for adjustment of the length of each the inflatable lap belts.
As stated, inflatable belts may include inflatable shoulder or inflatable lap belts. Each inflatable belt includes seat belt webbing having an interior cavity. An inflatable member may be disposed within the interior cavity. The belt webbing surrounding the inflatable member provides excellent protection to an inflatable member so that the inflatable member may properly deploy in an accident. Also, the seat belt webbing alleviates the need for additional costly and cumbersome protective devices to surround the inflatable members.
The seat belt webbing of the inflatable shoulder belts may also include a frangible seam that bursts upon inflation of an inflatable member. The frangible seam enables the inflatable members to fully inflate in an accident and provide protection to an occupant.
The inflatable seat belt system may also include a seat having two openings. The openings may be disposed within a fixed headrest of the seat. One of the shoulder belts passes through each of the openings. The openings helped to stabilize the inflatable seat belt system and maintain the correct position of the inflatable shoulder belts during an accident.
After passing through the openings, each of the inflatable shoulder belts may be attached to the rear side of the seat using a clamp or other retaining device. Alternatively, the inflatable shoulder belts may be attached to another portion of the vehicle, such as the floor.
In one embodiment, a separate inflator inflates each of the inflatable shoulder belts. Each inflator may be directly positioned within the corresponding inflatable member or may be in fluid communication with the inflatable member via a diffuser or gas guide. When two inflators are used, inflation of each of the inflatable shoulder belts may occur at different times or with varying amounts of filler medium (e.g., gas or foam). Thus, inflation sequences may vary according to the type of accident detected by sensors within the vehicle.
Alternatively, a single inflator may inflate both inflatable shoulder belts. Thus, the single inflator may be in fluid communication with both inflatable seat belts using, for instance, a diffuser or gas guide.
Each of the inflators described above may be attached to the rear side of the seat or could be positioned at other locations within the vehicle, such as within the seat. Also, each of the inflators described above could be in fluid communication with the inflatable lap belts. Alternatively, one or more separate inflators could be provided for inflation of the inflatable lap belts.
This invention presents a significant advancement in the art in that it provides superior protection to inflatable members of an inflatable seat belt system by surrounding each inflatable member with seat belt webbing. In addition, a cinching mechanism for adjusting the length of an inflatable belt is conveniently located for adjustment by an occupant. Also, openings within the seat, through which inflatable shoulder belts pass, provide additional stability to the inflatable seat belt system and help to maintain the inflatable shoulder belts in the correct position to protect an occupant during an accident.
These and other possible advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.